CVE-2025-31688 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the Drupal Configuration Split module, affecting versions prior to 1.10.0 in the 0.x branch and versions before 2.0.2 in the 2.x branch. Configuration Split is a Drupal module used to manage and maintain different configuration sets for various environments, such as development, staging, and production. The vulnerability arises because the module does not adequately verify the authenticity of requests that trigger configuration changes, allowing an attacker to craft malicious web requests that, when executed by an authenticated user, can alter configuration settings without their consent. This flaw is classified under CWE-352, which pertains to CSRF attacks where unauthorized commands are transmitted from a user that the web application trusts. The CVSS 3.1 base score of 6.8 reflects a medium severity, with the vector indicating network attack vector (AV:N), high attack complexity (AC:H), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), no confidentiality impact (C:N), but high impact on integrity (I:H) and availability (A:H). This means that while an attacker cannot directly compromise confidentiality, they can cause significant unauthorized changes to the system’s configuration and potentially disrupt service availability. Exploitation requires the victim to interact with a malicious link or site while authenticated to the affected Drupal instance. No known exploits are currently reported in the wild, and no official patches are linked yet, indicating that mitigation may rely on configuration hardening or temporary workarounds until updates are released. Given Drupal’s widespread use in content management across various sectors, this vulnerability poses a risk to any organization using the affected module versions, especially those with web-facing Drupal sites that rely on Configuration Split for environment management.

For European organizations, the impact of this vulnerability can be significant, particularly for entities relying on Drupal for critical web infrastructure such as government portals, educational institutions, healthcare providers, and large enterprises. Successful exploitation could lead to unauthorized modification of configuration settings, potentially causing service disruptions, misconfigurations that degrade security posture, or denial of service conditions. Since the vulnerability affects integrity and availability but not confidentiality, the primary risk lies in operational disruption and loss of trust in web services. Organizations with complex deployment environments using Configuration Split to manage multiple configurations are especially vulnerable, as attackers could manipulate environment-specific settings leading to inconsistent behavior or exposure of sensitive operational parameters. The requirement for user interaction and high attack complexity somewhat limits mass exploitation but targeted attacks against privileged users or administrators remain a realistic threat. The absence of known exploits suggests a window of opportunity for defenders to implement mitigations before widespread attacks occur.

Immediately audit Drupal instances to identify usage of the Configuration Split module and verify the installed versions. Prioritize upgrading to versions 1.10.0 or later in the 0.x branch and 2.0.2 or later in the 2.x branch once patches are available. Until patches are released, implement strict Content Security Policy (CSP) headers and SameSite cookie attributes to reduce the risk of CSRF by limiting cross-origin requests and cookie transmission. Enforce multi-factor authentication (MFA) for all Drupal administrative users to reduce the risk of session hijacking and unauthorized actions. Review and restrict user permissions to the minimum necessary, especially for roles that can modify configuration settings, to limit the potential impact of a successful CSRF attack. Monitor web server and Drupal logs for unusual POST requests or configuration changes initiated without proper authorization or outside normal maintenance windows. Educate users, especially administrators, about the risks of interacting with unknown or suspicious links while logged into Drupal administrative interfaces. Consider deploying Web Application Firewalls (WAF) with custom rules to detect and block suspicious CSRF attempts targeting the Configuration Split endpoints. If feasible, temporarily disable or restrict access to the Configuration Split module’s configuration interfaces from public or less trusted networks until a patch is applied.